He is obviously concerned to keep his good name. Assuming he can back up his narrative with facts in court, I cannot imagine Opera has a leg to stand on. If he

He is obviously concerned to keep his good name. Assuming he can back up his narrative with facts in court, I cannot imagine Opera has a leg to stand on. If he followed up the conversation with the CEO with a clear email, then there is documentation in place. That the CEO hasn't responded should have no bearing, as an oral agreement is considered as binding as a contract in Norway.